One of my biggest mistakes is being too conservative with money when I was young. My parents gave me savings to go to University with and I didn't spend a penny as I was saving for my future. I didn't realise that I could have spent an extra £3000 over those 3 years and had a tonne more fun than I did, going out, drinking, seeing bands and socialising. I thought that money was a massive amount at the time but it's not a great deal now.

My fuck buddy is trying to get into Drama school and she has to pay £100 an audition and said she couldn't afford to do more than a few. I asked her how much she spends a month on clothes and she told me £400. Drama school will be the best 3 years of her life (the UK does a low interest loan system so affordability isn't an issue once she is accepted) and it could set her up for a career in theatre, which she has wanted to do since she was a little girl. Once I pointed out that there was nothing more important in her life than getting to those auditions and doing well, she realised how silly she was being. (Isn't she lucky to have me to talk sense to her? Lol)

2 lessons here, money is a tool to do the things you love and apply your money to the point of maximum leverage in your life.